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Diffstat (limited to 'src/libexpr/eval.cc')
| -rw-r--r-- | src/libexpr/eval.cc | 1435 |
1 files changed, 1435 insertions, 0 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc new file mode 100644 index 000000000000..2087c7c43ffb --- /dev/null +++ b/src/libexpr/eval.cc @@ -0,0 +1,1435 @@ +#include "eval.hh" +#include "hash.hh" +#include "util.hh" +#include "store-api.hh" +#include "derivations.hh" +#include "globals.hh" +#include "eval-inline.hh" + +#include <cstring> +#include <unistd.h> +#include <sys/time.h> +#include <sys/resource.h> + +#if HAVE_BOEHMGC + +#include <gc/gc.h> +#include <gc/gc_cpp.h> + +#define NEW new (UseGC) + +#else + +#define GC_STRDUP strdup +#define GC_MALLOC malloc + +#define NEW new + +#endif + + +namespace nix { + + +Bindings::iterator Bindings::find(const Symbol & name) +{ + Attr key(name, 0); + iterator i = lower_bound(begin(), end(), key); + if (i != end() && i->name == name) return i; + return end(); +} + + +void Bindings::sort() +{ + std::sort(begin(), end()); +} + + +std::ostream & operator << (std::ostream & str, const Value & v) +{ + switch (v.type) { + case tInt: + str << v.integer; + break; + case tBool: + str << (v.boolean ? "true" : "false"); + break; + case tString: + str << "\""; + for (const char * i = v.string.s; *i; i++) + if (*i == '\"' || *i == '\\') str << "\\" << *i; + else if (*i == '\n') str << "\\n"; + else if (*i == '\r') str << "\\r"; + else if (*i == '\t') str << "\\t"; + else str << *i; + str << "\""; + break; + case tPath: + str << v.path; // !!! escaping? + break; + case tNull: + str << "null"; + break; + case tAttrs: { + str << "{ "; + typedef std::map<string, Value *> Sorted; + Sorted sorted; + foreach (Bindings::iterator, i, *v.attrs) + sorted[i->name] = i->value; + foreach (Sorted::iterator, i, sorted) + str << i->first << " = " << *i->second << "; "; + str << "}"; + break; + } + case tList: + str << "[ "; + for (unsigned int n = 0; n < v.list.length; ++n) + str << *v.list.elems[n] << " "; + str << "]"; + break; + case tThunk: + case tApp: + str << "<CODE>"; + break; + case tLambda: + str << "<LAMBDA>"; + break; + case tPrimOp: + str << "<PRIMOP>"; + break; + case tPrimOpApp: + str << "<PRIMOP-APP>"; + break; + default: + throw Error("invalid value"); + } + return str; +} + + +string showType(const Value & v) +{ + switch (v.type) { + case tInt: return "an integer"; + case tBool: return "a boolean"; + case tString: return "a string"; + case tPath: return "a path"; + case tNull: return "null"; + case tAttrs: return "a set"; + case tList: return "a list"; + case tThunk: return "a thunk"; + case tApp: return "a function application"; + case tLambda: return "a function"; + case tBlackhole: return "a black hole"; + case tPrimOp: return "a built-in function"; + case tPrimOpApp: return "a partially applied built-in function"; + } + abort(); +} + + +/* Called when the Boehm GC runs out of memory. */ +static void * oomHandler(size_t requested) +{ + /* Convert this to a proper C++ exception. */ + throw std::bad_alloc(); +} + + +static Symbol getName(const AttrName & name, EvalState & state, Env & env) { + if (name.symbol.set()) { + return name.symbol; + } else { + Value nameValue; + name.expr->eval(state, env, nameValue); + state.forceStringNoCtx(nameValue); + return state.symbols.create(nameValue.string.s); + } +} + + +EvalState::EvalState() + : sWith(symbols.create("<with>")) + , sOutPath(symbols.create("outPath")) + , sDrvPath(symbols.create("drvPath")) + , sType(symbols.create("type")) + , sMeta(symbols.create("meta")) + , sName(symbols.create("name")) + , sValue(symbols.create("value")) + , sSystem(symbols.create("system")) + , sOverrides(symbols.create("__overrides")) + , sOutputs(symbols.create("outputs")) + , sOutputName(symbols.create("outputName")) + , sIgnoreNulls(symbols.create("__ignoreNulls")) + , sFile(symbols.create("file")) + , sLine(symbols.create("line")) + , sColumn(symbols.create("column")) + , repair(false) + , baseEnv(allocEnv(128)) + , staticBaseEnv(false, 0) + , baseEnvDispl(0) +{ + nrEnvs = nrValuesInEnvs = nrValues = nrListElems = 0; + nrAttrsets = nrOpUpdates = nrOpUpdateValuesCopied = 0; + nrListConcats = nrPrimOpCalls = nrFunctionCalls = 0; + countCalls = getEnv("NIX_COUNT_CALLS", "0") != "0"; + +#if HAVE_BOEHMGC + static bool gcInitialised = false; + if (!gcInitialised) { + + /* Initialise the Boehm garbage collector. This isn't + necessary on most platforms, but for portability we do it + anyway. */ + GC_INIT(); + + GC_oom_fn = oomHandler; + + /* Set the initial heap size to something fairly big (25% of + physical RAM, up to a maximum of 384 MiB) so that in most + cases we don't need to garbage collect at all. (Collection + has a fairly significant overhead.) The heap size can be + overridden through libgc's GC_INITIAL_HEAP_SIZE environment + variable. We should probably also provide a nix.conf + setting for this. Note that GC_expand_hp() causes a lot of + virtual, but not physical (resident) memory to be + allocated. This might be a problem on systems that don't + overcommit. */ + if (!getenv("GC_INITIAL_HEAP_SIZE")) { + size_t maxSize = 384 * 1024 * 1024; + size_t size = 32 * 1024 * 1024; +#if HAVE_SYSCONF && defined(_SC_PAGESIZE) && defined(_SC_PHYS_PAGES) + long pageSize = sysconf(_SC_PAGESIZE); + long pages = sysconf(_SC_PHYS_PAGES); + if (pageSize != -1) + size = (pageSize * pages) / 4; // 25% of RAM + if (size > maxSize) size = maxSize; +#endif + debug(format("setting initial heap size to %1% bytes") % size); + GC_expand_hp(size); + } + + gcInitialised = true; + } +#endif + + /* Initialise the Nix expression search path. */ + searchPathInsertionPoint = searchPath.end(); + Strings paths = tokenizeString<Strings>(getEnv("NIX_PATH", ""), ":"); + foreach (Strings::iterator, i, paths) addToSearchPath(*i); + addToSearchPath("nix=" + settings.nixDataDir + "/nix/corepkgs"); + searchPathInsertionPoint = searchPath.begin(); + + createBaseEnv(); +} + + +EvalState::~EvalState() +{ +} + + +void EvalState::addConstant(const string & name, Value & v) +{ + Value * v2 = allocValue(); + *v2 = v; + staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; + baseEnv.values[baseEnvDispl++] = v2; + string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; + baseEnv.values[0]->attrs->push_back(Attr(symbols.create(name2), v2)); +} + + +void EvalState::addPrimOp(const string & name, + unsigned int arity, PrimOpFun primOp) +{ + Value * v = allocValue(); + string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; + Symbol sym = symbols.create(name2); + v->type = tPrimOp; + v->primOp = NEW PrimOp(primOp, arity, sym); + staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; + baseEnv.values[baseEnvDispl++] = v; + baseEnv.values[0]->attrs->push_back(Attr(sym, v)); +} + + +void EvalState::getBuiltin(const string & name, Value & v) +{ + v = *baseEnv.values[0]->attrs->find(symbols.create(name))->value; +} + + +/* Every "format" object (even temporary) takes up a few hundred bytes + of stack space, which is a real killer in the recursive + evaluator. So here are some helper functions for throwing + exceptions. */ + +LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2)) +{ + throw EvalError(format(s) % s2); +} + +LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2, const string & s3)) +{ + throw EvalError(format(s) % s2 % s3); +} + +LocalNoInlineNoReturn(void throwEvalError(const char * s, const Symbol & sym, const Pos & p1, const Pos & p2)) +{ + throw EvalError(format(s) % sym % p1 % p2); +} + +LocalNoInlineNoReturn(void throwTypeError(const char * s)) +{ + throw TypeError(s); +} + +LocalNoInlineNoReturn(void throwTypeError(const char * s, const string & s1)) +{ + throw TypeError(format(s) % s1); +} + +LocalNoInlineNoReturn(void throwTypeError(const char * s, const string & s1, const string & s2)) +{ + throw TypeError(format(s) % s1 % s2); +} + +LocalNoInlineNoReturn(void throwTypeError(const char * s, const ExprLambda & fun, const Symbol & s2)) +{ + throw TypeError(format(s) % fun.showNamePos() % s2); +} + +LocalNoInlineNoReturn(void throwAssertionError(const char * s, const Pos & pos)) +{ + throw AssertionError(format(s) % pos); +} + +LocalNoInlineNoReturn(void throwUndefinedVarError(const char * s, const string & s1, const Pos & pos)) +{ + throw UndefinedVarError(format(s) % s1 % pos); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2)) +{ + e.addPrefix(format(s) % s2); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s, const ExprLambda & fun)) +{ + e.addPrefix(format(s) % fun.showNamePos()); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2, const Pos & pos)) +{ + e.addPrefix(format(s) % s2 % pos); +} + + +void mkString(Value & v, const char * s) +{ + mkStringNoCopy(v, GC_STRDUP(s)); +} + + +void mkString(Value & v, const string & s, const PathSet & context) +{ + mkString(v, s.c_str()); + if (!context.empty()) { + unsigned int n = 0; + v.string.context = (const char * *) + GC_MALLOC((context.size() + 1) * sizeof(char *)); + foreach (PathSet::const_iterator, i, context) + v.string.context[n++] = GC_STRDUP(i->c_str()); + v.string.context[n] = 0; + } +} + + +void mkPath(Value & v, const char * s) +{ + mkPathNoCopy(v, GC_STRDUP(s)); +} + + +inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval) +{ + for (unsigned int l = var.level; l; --l, env = env->up) ; + + if (!var.fromWith) return env->values[var.displ]; + + while (1) { + if (!env->haveWithAttrs) { + if (noEval) return 0; + Value * v = allocValue(); + evalAttrs(*env->up, (Expr *) env->values[0], *v); + env->values[0] = v; + env->haveWithAttrs = true; + } + Bindings::iterator j = env->values[0]->attrs->find(var.name); + if (j != env->values[0]->attrs->end()) { + if (countCalls && j->pos) attrSelects[*j->pos]++; + return j->value; + } + if (!env->prevWith) + throwUndefinedVarError("undefined variable `%1%' at %2%", var.name, var.pos); + for (unsigned int l = env->prevWith; l; --l, env = env->up) ; + } +} + + +Value * EvalState::allocValue() +{ + nrValues++; + return (Value *) GC_MALLOC(sizeof(Value)); +} + + +Env & EvalState::allocEnv(unsigned int size) +{ + nrEnvs++; + nrValuesInEnvs += size; + Env * env = (Env *) GC_MALLOC(sizeof(Env) + size * sizeof(Value *)); + + /* Clear the values because maybeThunk() and lookupVar fromWith expects this. */ + for (unsigned i = 0; i < size; ++i) + env->values[i] = 0; + + return *env; +} + + +Value * EvalState::allocAttr(Value & vAttrs, const Symbol & name) +{ + Value * v = allocValue(); + vAttrs.attrs->push_back(Attr(name, v)); + return v; +} + + +void EvalState::mkList(Value & v, unsigned int length) +{ + v.type = tList; + v.list.length = length; + v.list.elems = length ? (Value * *) GC_MALLOC(length * sizeof(Value *)) : 0; + nrListElems += length; +} + + +void EvalState::mkAttrs(Value & v, unsigned int expected) +{ + clearValue(v); + v.type = tAttrs; + v.attrs = NEW Bindings; + v.attrs->reserve(expected); + nrAttrsets++; +} + + +unsigned long nrThunks = 0; + +static inline void mkThunk(Value & v, Env & env, Expr * expr) +{ + v.type = tThunk; + v.thunk.env = &env; + v.thunk.expr = expr; + nrThunks++; +} + + +void EvalState::mkThunk_(Value & v, Expr * expr) +{ + mkThunk(v, baseEnv, expr); +} + + +void EvalState::mkPos(Value & v, Pos * pos) +{ + if (pos) { + mkAttrs(v, 3); + mkString(*allocAttr(v, sFile), pos->file); + mkInt(*allocAttr(v, sLine), pos->line); + mkInt(*allocAttr(v, sColumn), pos->column); + v.attrs->sort(); + } else + mkNull(v); +} + + +/* Create a thunk for the delayed computation of the given expression + in the given environment. But if the expression is a variable, + then look it up right away. This significantly reduces the number + of thunks allocated. */ +Value * Expr::maybeThunk(EvalState & state, Env & env) +{ + Value * v = state.allocValue(); + mkThunk(*v, env, this); + return v; +} + + +unsigned long nrAvoided = 0; + +Value * ExprVar::maybeThunk(EvalState & state, Env & env) +{ + Value * v = state.lookupVar(&env, *this, true); + /* The value might not be initialised in the environment yet. + In that case, ignore it. */ + if (v) { nrAvoided++; return v; } + return Expr::maybeThunk(state, env); +} + + +Value * ExprString::maybeThunk(EvalState & state, Env & env) +{ + nrAvoided++; + return &v; +} + +Value * ExprInt::maybeThunk(EvalState & state, Env & env) +{ + nrAvoided++; + return &v; +} + +Value * ExprPath::maybeThunk(EvalState & state, Env & env) +{ + nrAvoided++; + return &v; +} + + +void EvalState::evalFile(const Path & path, Value & v) +{ + FileEvalCache::iterator i; + if ((i = fileEvalCache.find(path)) != fileEvalCache.end()) { + v = i->second; + return; + } + + Path path2 = resolveExprPath(path); + if ((i = fileEvalCache.find(path2)) != fileEvalCache.end()) { + v = i->second; + return; + } + + startNest(nest, lvlTalkative, format("evaluating file `%1%'") % path2); + Expr * e = parseExprFromFile(path2); + try { + eval(e, v); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the file `%1%':\n", path2); + throw; + } + + fileEvalCache[path2] = v; + if (path != path2) fileEvalCache[path] = v; +} + + +void EvalState::resetFileCache() +{ + fileEvalCache.clear(); +} + + +void EvalState::eval(Expr * e, Value & v) +{ + e->eval(*this, baseEnv, v); +} + + +inline bool EvalState::evalBool(Env & env, Expr * e, Value & v) +{ + e->eval(*this, env, v); + if (v.type != tBool) + throwTypeError("value is %1% while a Boolean was expected", v); + return v.boolean; +} + + +inline bool EvalState::evalBool(Env & env, Expr * e) +{ + Value v; + return evalBool(env, e, v); +} + + +inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v) +{ + e->eval(*this, env, v); + if (v.type != tAttrs) + throwTypeError("value is %1% while a set was expected", v); +} + + +void Expr::eval(EvalState & state, Env & env, Value & v) +{ + abort(); +} + + +void ExprInt::eval(EvalState & state, Env & env, Value & v) +{ + v = this->v; +} + + +void ExprString::eval(EvalState & state, Env & env, Value & v) +{ + v = this->v; +} + + +void ExprPath::eval(EvalState & state, Env & env, Value & v) +{ + v = this->v; +} + + +void ExprAttrs::eval(EvalState & state, Env & env, Value & v) +{ + state.mkAttrs(v, attrs.size()); + Env *dynamicEnv = &env; + + if (recursive) { + /* Create a new environment that contains the attributes in + this `rec'. */ + Env & env2(state.allocEnv(attrs.size())); + env2.up = &env; + dynamicEnv = &env2; + + AttrDefs::iterator overrides = attrs.find(state.sOverrides); + bool hasOverrides = overrides != attrs.end(); + + /* The recursive attributes are evaluated in the new + environment, while the inherited attributes are evaluated + in the original environment. */ + unsigned int displ = 0; + foreach (AttrDefs::iterator, i, attrs) { + Value * vAttr; + if (hasOverrides && !i->second.inherited) { + vAttr = state.allocValue(); + mkThunk(*vAttr, env2, i->second.e); + } else + vAttr = i->second.e->maybeThunk(state, i->second.inherited ? env : env2); + env2.values[displ++] = vAttr; + v.attrs->push_back(Attr(i->first, vAttr, &i->second.pos)); + } + + /* If the rec contains an attribute called `__overrides', then + evaluate it, and add the attributes in that set to the rec. + This allows overriding of recursive attributes, which is + otherwise not possible. (You can use the // operator to + replace an attribute, but other attributes in the rec will + still reference the original value, because that value has + been substituted into the bodies of the other attributes. + Hence we need __overrides.) */ + if (hasOverrides) { + Value * vOverrides = (*v.attrs)[overrides->second.displ].value; + state.forceAttrs(*vOverrides); + foreach (Bindings::iterator, i, *vOverrides->attrs) { + AttrDefs::iterator j = attrs.find(i->name); + if (j != attrs.end()) { + (*v.attrs)[j->second.displ] = *i; + env2.values[j->second.displ] = i->value; + } else + v.attrs->push_back(*i); + } + v.attrs->sort(); + } + } + + else + foreach (AttrDefs::iterator, i, attrs) + v.attrs->push_back(Attr(i->first, i->second.e->maybeThunk(state, env), &i->second.pos)); + + /* dynamic attrs apply *after* rec and __overrides */ + foreach (DynamicAttrDefs::iterator, i, dynamicAttrs) { + Value nameVal; + i->nameExpr->eval(state, *dynamicEnv, nameVal); + state.forceStringNoCtx(nameVal); + Symbol nameSym = state.symbols.create(nameVal.string.s); + Bindings::iterator j = v.attrs->find(nameSym); + if (j != v.attrs->end()) + throwEvalError("dynamic attribute `%1%' at %2% already defined at %3%", nameSym, i->pos, *j->pos); + + i->valueExpr->setName(nameSym); + /* Keep sorted order so find can catch duplicates */ + v.attrs->insert(lower_bound(v.attrs->begin(), v.attrs->end(), Attr(nameSym, 0)), + Attr(nameSym, i->valueExpr->maybeThunk(state, *dynamicEnv), &i->pos)); + } +} + + +void ExprLet::eval(EvalState & state, Env & env, Value & v) +{ + /* Create a new environment that contains the attributes in this + `let'. */ + Env & env2(state.allocEnv(attrs->attrs.size())); + env2.up = &env; + + /* The recursive attributes are evaluated in the new environment, + while the inherited attributes are evaluated in the original + environment. */ + unsigned int displ = 0; + foreach (ExprAttrs::AttrDefs::iterator, i, attrs->attrs) + env2.values[displ++] = i->second.e->maybeThunk(state, i->second.inherited ? env : env2); + + body->eval(state, env2, v); +} + + +void ExprList::eval(EvalState & state, Env & env, Value & v) +{ + state.mkList(v, elems.size()); + for (unsigned int n = 0; n < v.list.length; ++n) + v.list.elems[n] = elems[n]->maybeThunk(state, env); +} + + +void ExprVar::eval(EvalState & state, Env & env, Value & v) +{ + Value * v2 = state.lookupVar(&env, *this, false); + state.forceValue(*v2); + v = *v2; +} + + +unsigned long nrLookups = 0; + +void ExprSelect::eval(EvalState & state, Env & env, Value & v) +{ + Value vTmp; + Pos * pos = 0; + Value * vAttrs = &vTmp; + + e->eval(state, env, vTmp); + + try { + + foreach (AttrPath::const_iterator, i, attrPath) { + nrLookups++; + Bindings::iterator j; + Symbol name = getName(*i, state, env); + if (def) { + state.forceValue(*vAttrs); + if (vAttrs->type != tAttrs || + (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) + { + def->eval(state, env, v); + return; + } + } else { + state.forceAttrs(*vAttrs); + if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) + throwEvalError("attribute `%1%' missing", showAttrPath(attrPath)); + } + vAttrs = j->value; + pos = j->pos; + if (state.countCalls && pos) state.attrSelects[*pos]++; + } + + state.forceValue(*vAttrs); + + } catch (Error & e) { + if (pos && pos->file != state.sDerivationNix) + addErrorPrefix(e, "while evaluating the attribute `%1%' at %2%:\n", + showAttrPath(attrPath), *pos); + throw; + } + + v = *vAttrs; +} + + +void ExprOpHasAttr::eval(EvalState & state, Env & env, Value & v) +{ + Value vTmp; + Value * vAttrs = &vTmp; + + e->eval(state, env, vTmp); + + foreach (AttrPath::const_iterator, i, attrPath) { + state.forceValue(*vAttrs); + Bindings::iterator j; + Symbol name = getName(*i, state, env); + if (vAttrs->type != tAttrs || + (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) + { + mkBool(v, false); + return; + } else { + vAttrs = j->value; + } + } + + mkBool(v, true); +} + + +void ExprLambda::eval(EvalState & state, Env & env, Value & v) +{ + v.type = tLambda; + v.lambda.env = &env; + v.lambda.fun = this; +} + + +void ExprApp::eval(EvalState & state, Env & env, Value & v) +{ + e1->eval(state, env, v); + state.callFunction(v, *(e2->maybeThunk(state, env)), v); +} + + +void EvalState::callPrimOp(Value & fun, Value & arg, Value & v) +{ + /* Figure out the number of arguments still needed. */ + unsigned int argsDone = 0; + Value * primOp = &fun; + while (primOp->type == tPrimOpApp) { + argsDone++; + primOp = primOp->primOpApp.left; + } + assert(primOp->type == tPrimOp); + unsigned int arity = primOp->primOp->arity; + unsigned int argsLeft = arity - argsDone; + + if (argsLeft == 1) { + /* We have all the arguments, so call the primop. */ + + /* Put all the arguments in an array. */ + Value * vArgs[arity]; + unsigned int n = arity - 1; + vArgs[n--] = &arg; + for (Value * arg = &fun; arg->type == tPrimOpApp; arg = arg->primOpApp.left) + vArgs[n--] = arg->primOpApp.right; + + /* And call the primop. */ + nrPrimOpCalls++; + if (countCalls) primOpCalls[primOp->primOp->name]++; + primOp->primOp->fun(*this, vArgs, v); + } else { + Value * fun2 = allocValue(); + *fun2 = fun; + v.type = tPrimOpApp; + v.primOpApp.left = fun2; + v.primOpApp.right = &arg; + } +} + + +void EvalState::callFunction(Value & fun, Value & arg, Value & v) +{ + if (fun.type == tPrimOp || fun.type == tPrimOpApp) { + callPrimOp(fun, arg, v); + return; + } + + if (fun.type != tLambda) + throwTypeError("attempt to call something which is not a function but %1%", fun); + + ExprLambda & lambda(*fun.lambda.fun); + + unsigned int size = + (lambda.arg.empty() ? 0 : 1) + + (lambda.matchAttrs ? lambda.formals->formals.size() : 0); + Env & env2(allocEnv(size)); + env2.up = fun.lambda.env; + + unsigned int displ = 0; + + if (!lambda.matchAttrs) + env2.values[displ++] = &arg; + + else { + forceAttrs(arg); + + if (!lambda.arg.empty()) + env2.values[displ++] = &arg; + + /* For each formal argument, get the actual argument. If + there is no matching actual argument but the formal + argument has a default, use the default. */ + unsigned int attrsUsed = 0; + foreach (Formals::Formals_::iterator, i, lambda.formals->formals) { + Bindings::iterator j = arg.attrs->find(i->name); + if (j == arg.attrs->end()) { + if (!i->def) throwTypeError("%1% called without required argument `%2%'", + lambda, i->name); + env2.values[displ++] = i->def->maybeThunk(*this, env2); + } else { + attrsUsed++; + env2.values[displ++] = j->value; + } + } + + /* Check that each actual argument is listed as a formal + argument (unless the attribute match specifies a `...'). */ + if (!lambda.formals->ellipsis && attrsUsed != arg.attrs->size()) { + /* Nope, so show the first unexpected argument to the + user. */ + foreach (Bindings::iterator, i, *arg.attrs) + if (lambda.formals->argNames.find(i->name) == lambda.formals->argNames.end()) + throwTypeError("%1% called with unexpected argument `%2%'", lambda, i->name); + abort(); // can't happen + } + } + + nrFunctionCalls++; + if (countCalls) incrFunctionCall(&lambda); + + /* Evaluate the body. This is conditional on showTrace, because + catching exceptions makes this function not tail-recursive. */ + if (settings.showTrace) + try { + lambda.body->eval(*this, env2, v); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating %1%:\n", lambda); + throw; + } + else + fun.lambda.fun->body->eval(*this, env2, v); +} + + +// Lifted out of callFunction() because it creates a temporary that +// prevents tail-call optimisation. +void EvalState::incrFunctionCall(ExprLambda * fun) +{ + functionCalls[fun]++; +} + + +void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res) +{ + forceValue(fun); + + if (fun.type != tLambda || !fun.lambda.fun->matchAttrs) { + res = fun; + return; + } + + Value * actualArgs = allocValue(); + mkAttrs(*actualArgs, fun.lambda.fun->formals->formals.size()); + + foreach (Formals::Formals_::iterator, i, fun.lambda.fun->formals->formals) { + Bindings::iterator j = args.find(i->name); + if (j != args.end()) + actualArgs->attrs->push_back(*j); + else if (!i->def) + throwTypeError("cannot auto-call a function that has an argument without a default value (`%1%')", i->name); + } + + actualArgs->attrs->sort(); + + callFunction(fun, *actualArgs, res); +} + + +void ExprWith::eval(EvalState & state, Env & env, Value & v) +{ + Env & env2(state.allocEnv(1)); + env2.up = &env; + env2.prevWith = prevWith; + env2.haveWithAttrs = false; + env2.values[0] = (Value *) attrs; + + body->eval(state, env2, v); +} + + +void ExprIf::eval(EvalState & state, Env & env, Value & v) +{ + (state.evalBool(env, cond, v) ? then : else_)->eval(state, env, v); +} + + +void ExprAssert::eval(EvalState & state, Env & env, Value & v) +{ + if (!state.evalBool(env, cond, v)) + throwAssertionError("assertion failed at %1%", pos); + body->eval(state, env, v); +} + + +void ExprOpNot::eval(EvalState & state, Env & env, Value & v) +{ + mkBool(v, !state.evalBool(env, e)); +} + + +void ExprBuiltin::eval(EvalState & state, Env & env, Value & v) +{ + // Not a hot path at all, but would be nice to access state.baseEnv directly + Env *baseEnv = &env; + while (baseEnv->up) baseEnv = baseEnv->up; + Bindings::iterator binding = baseEnv->values[0]->attrs->find(name); + assert(binding != baseEnv->values[0]->attrs->end()); + v = *binding->value; +} + + +void ExprOpEq::eval(EvalState & state, Env & env, Value & v) +{ + Value v1; e1->eval(state, env, v1); + Value v2; e2->eval(state, env, v2); + mkBool(v, state.eqValues(v1, v2)); +} + + +void ExprOpNEq::eval(EvalState & state, Env & env, Value & v) +{ + Value v1; e1->eval(state, env, v1); + Value v2; e2->eval(state, env, v2); + mkBool(v, !state.eqValues(v1, v2)); +} + + +void ExprOpAnd::eval(EvalState & state, Env & env, Value & v) +{ + mkBool(v, state.evalBool(env, e1) && state.evalBool(env, e2)); +} + + +void ExprOpOr::eval(EvalState & state, Env & env, Value & v) +{ + mkBool(v, state.evalBool(env, e1) || state.evalBool(env, e2)); +} + + +void ExprOpImpl::eval(EvalState & state, Env & env, Value & v) +{ + mkBool(v, !state.evalBool(env, e1) || state.evalBool(env, e2)); +} + + +void ExprOpUpdate::eval(EvalState & state, Env & env, Value & v) +{ + Value v1, v2; + state.evalAttrs(env, e1, v1); + state.evalAttrs(env, e2, v2); + + state.nrOpUpdates++; + + if (v1.attrs->size() == 0) { v = v2; return; } + if (v2.attrs->size() == 0) { v = v1; return; } + + state.mkAttrs(v, v1.attrs->size() + v2.attrs->size()); + + /* Merge the sets, preferring values from the second set. Make + sure to keep the resulting vector in sorted order. */ + Bindings::iterator i = v1.attrs->begin(); + Bindings::iterator j = v2.attrs->begin(); + + while (i != v1.attrs->end() && j != v2.attrs->end()) { + if (i->name == j->name) { + v.attrs->push_back(*j); + ++i; ++j; + } + else if (i->name < j->name) + v.attrs->push_back(*i++); + else + v.attrs->push_back(*j++); + } + + while (i != v1.attrs->end()) v.attrs->push_back(*i++); + while (j != v2.attrs->end()) v.attrs->push_back(*j++); + + state.nrOpUpdateValuesCopied += v.attrs->size(); +} + + +void ExprOpConcatLists::eval(EvalState & state, Env & env, Value & v) +{ + Value v1; e1->eval(state, env, v1); + Value v2; e2->eval(state, env, v2); + Value * lists[2] = { &v1, &v2 }; + state.concatLists(v, 2, lists); +} + + +void EvalState::concatLists(Value & v, unsigned int nrLists, Value * * lists) +{ + nrListConcats++; + + Value * nonEmpty = 0; + unsigned int len = 0; + for (unsigned int n = 0; n < nrLists; ++n) { + forceList(*lists[n]); + unsigned int l = lists[n]->list.length; + len += l; + if (l) nonEmpty = lists[n]; + } + + if (nonEmpty && len == nonEmpty->list.length) { + v = *nonEmpty; + return; + } + + mkList(v, len); + for (unsigned int n = 0, pos = 0; n < nrLists; ++n) { + unsigned int l = lists[n]->list.length; + memcpy(v.list.elems + pos, lists[n]->list.elems, l * sizeof(Value *)); + pos += l; + } +} + + +void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v) +{ + PathSet context; + std::ostringstream s; + NixInt n = 0; + + bool first = !forceString; + ValueType firstType = tString; + + foreach (vector<Expr *>::iterator, i, *es) { + Value vTmp; + (*i)->eval(state, env, vTmp); + + /* If the first element is a path, then the result will also + be a path, we don't copy anything (yet - that's done later, + since paths are copied when they are used in a derivation), + and none of the strings are allowed to have contexts. */ + if (first) { + firstType = vTmp.type; + first = false; + } + + if (firstType == tInt) { + if (vTmp.type != tInt) + throwEvalError("cannot add %1% to an integer", showType(vTmp)); + n += vTmp.integer; + } else + s << state.coerceToString(vTmp, context, false, firstType == tString); + } + + if (firstType == tInt) + mkInt(v, n); + else if (firstType == tPath) { + if (!context.empty()) + throwEvalError("a string that refers to a store path cannot be appended to a path, in `%1%'", s.str()); + mkPath(v, s.str().c_str()); + } else + mkString(v, s.str(), context); +} + + +void ExprPos::eval(EvalState & state, Env & env, Value & v) +{ + state.mkPos(v, &pos); +} + + +void EvalState::strictForceValue(Value & v) +{ + forceValue(v); + + if (v.type == tAttrs) { + foreach (Bindings::iterator, i, *v.attrs) + strictForceValue(*i->value); + } + + else if (v.type == tList) { + for (unsigned int n = 0; n < v.list.length; ++n) + strictForceValue(*v.list.elems[n]); + } +} + + +NixInt EvalState::forceInt(Value & v) +{ + forceValue(v); + if (v.type != tInt) + throwTypeError("value is %1% while an integer was expected", v); + return v.integer; +} + + +bool EvalState::forceBool(Value & v) +{ + forceValue(v); + if (v.type != tBool) + throwTypeError("value is %1% while a Boolean was expected", v); + return v.boolean; +} + + +void EvalState::forceFunction(Value & v) +{ + forceValue(v); + if (v.type != tLambda && v.type != tPrimOp && v.type != tPrimOpApp) + throwTypeError("value is %1% while a function was expected", v); +} + + +string EvalState::forceString(Value & v) +{ + forceValue(v); + if (v.type != tString) + throwTypeError("value is %1% while a string was expected", v); + return string(v.string.s); +} + + +void copyContext(const Value & v, PathSet & context) +{ + if (v.string.context) + for (const char * * p = v.string.context; *p; ++p) + context.insert(*p); +} + + +string EvalState::forceString(Value & v, PathSet & context) +{ + string s = forceString(v); + copyContext(v, context); + return s; +} + + +string EvalState::forceStringNoCtx(Value & v) +{ + string s = forceString(v); + if (v.string.context) + throwEvalError("the string `%1%' is not allowed to refer to a store path (such as `%2%')", + v.string.s, v.string.context[0]); + return s; +} + + +bool EvalState::isDerivation(Value & v) +{ + if (v.type != tAttrs) return false; + Bindings::iterator i = v.attrs->find(sType); + if (i == v.attrs->end()) return false; + forceValue(*i->value); + if (i->value->type != tString) return false; + return strcmp(i->value->string.s, "derivation") == 0; +} + + +string EvalState::coerceToString(Value & v, PathSet & context, + bool coerceMore, bool copyToStore) +{ + forceValue(v); + + string s; + + if (v.type == tString) { + copyContext(v, context); + return v.string.s; + } + + if (v.type == tPath) { + Path path(canonPath(v.path)); + return copyToStore ? copyPathToStore(context, path) : path; + } + + if (v.type == tAttrs) { + Bindings::iterator i = v.attrs->find(sOutPath); + if (i == v.attrs->end()) throwTypeError("cannot coerce a set to a string"); + return coerceToString(*i->value, context, coerceMore, copyToStore); + } + + if (coerceMore) { + + /* Note that `false' is represented as an empty string for + shell scripting convenience, just like `null'. */ + if (v.type == tBool && v.boolean) return "1"; + if (v.type == tBool && !v.boolean) return ""; + if (v.type == tInt) return int2String(v.integer); + if (v.type == tNull) return ""; + + if (v.type == tList) { + string result; + for (unsigned int n = 0; n < v.list.length; ++n) { + result += coerceToString(*v.list.elems[n], + context, coerceMore, copyToStore); + if (n < v.list.length - 1 + /* !!! not quite correct */ + && (v.list.elems[n]->type != tList || v.list.elems[n]->list.length != 0)) + result += " "; + } + return result; + } + } + + throwTypeError("cannot coerce %1% to a string", v); +} + + +string EvalState::copyPathToStore(PathSet & context, const Path & path) +{ + if (nix::isDerivation(path)) + throwEvalError("file names are not allowed to end in `%1%'", drvExtension); + + Path dstPath; + if (srcToStore[path] != "") + dstPath = srcToStore[path]; + else { + dstPath = settings.readOnlyMode + ? computeStorePathForPath(path).first + : store->addToStore(path, true, htSHA256, defaultPathFilter, repair); + srcToStore[path] = dstPath; + printMsg(lvlChatty, format("copied source `%1%' -> `%2%'") + % path % dstPath); + } + + context.insert(dstPath); + return dstPath; +} + + +Path EvalState::coerceToPath(Value & v, PathSet & context) +{ + string path = coerceToString(v, context, false, false); + if (path == "" || path[0] != '/') + throwEvalError("string `%1%' doesn't represent an absolute path", path); + return path; +} + + +bool EvalState::eqValues(Value & v1, Value & v2) +{ + forceValue(v1); + forceValue(v2); + + /* !!! Hack to support some old broken code that relies on pointer + equality tests between sets. (Specifically, builderDefs calls + uniqList on a list of sets.) Will remove this eventually. */ + if (&v1 == &v2) return true; + + if (v1.type != v2.type) return false; + + switch (v1.type) { + + case tInt: + return v1.integer == v2.integer; + + case tBool: + return v1.boolean == v2.boolean; + + case tString: { + /* Compare both the string and its context. */ + if (strcmp(v1.string.s, v2.string.s) != 0) return false; + const char * * p = v1.string.context, * * q = v2.string.context; + if (!p && !q) return true; + if (!p || !q) return false; + for ( ; *p && *q; ++p, ++q) + if (strcmp(*p, *q) != 0) return false; + if (*p || *q) return false; + return true; + } + + case tPath: + return strcmp(v1.path, v2.path) == 0; + + case tNull: + return true; + + case tList: + if (v1.list.length != v2.list.length) return false; + for (unsigned int n = 0; n < v1.list.length; ++n) + if (!eqValues(*v1.list.elems[n], *v2.list.elems[n])) return false; + return true; + + case tAttrs: { + /* If both sets denote a derivation (type = "derivation"), + then compare their outPaths. */ + if (isDerivation(v1) && isDerivation(v2)) { + Bindings::iterator i = v1.attrs->find(sOutPath); + Bindings::iterator j = v2.attrs->find(sOutPath); + if (i != v1.attrs->end() && j != v2.attrs->end()) + return eqValues(*i->value, *j->value); + } + + if (v1.attrs->size() != v2.attrs->size()) return false; + + /* Otherwise, compare the attributes one by one. */ + Bindings::iterator i, j; + for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j) + if (i->name != j->name || !eqValues(*i->value, *j->value)) + return false; + + return true; + } + + /* Functions are incomparable. */ + case tLambda: + case tPrimOp: + case tPrimOpApp: + return false; + + default: + throwEvalError("cannot compare %1% with %2%", showType(v1), showType(v2)); + } +} + + +void EvalState::printStats() +{ + bool showStats = getEnv("NIX_SHOW_STATS", "0") != "0"; + Verbosity v = showStats ? lvlInfo : lvlDebug; + printMsg(v, "evaluation statistics:"); + + struct rusage buf; + getrusage(RUSAGE_SELF, &buf); + float cpuTime = buf.ru_utime.tv_sec + ((float) buf.ru_utime.tv_usec / 1000000); + + printMsg(v, format(" time elapsed: %1%") % cpuTime); + printMsg(v, format(" size of a value: %1%") % sizeof(Value)); + printMsg(v, format(" environments allocated: %1% (%2% bytes)") + % nrEnvs % (nrEnvs * sizeof(Env) + nrValuesInEnvs * sizeof(Value *))); + printMsg(v, format(" list elements: %1% (%2% bytes)") + % nrListElems % (nrListElems * sizeof(Value *))); + printMsg(v, format(" list concatenations: %1%") % nrListConcats); + printMsg(v, format(" values allocated: %1% (%2% bytes)") + % nrValues % (nrValues * sizeof(Value))); + printMsg(v, format(" sets allocated: %1%") % nrAttrsets); + printMsg(v, format(" right-biased unions: %1%") % nrOpUpdates); + printMsg(v, format(" values copied in right-biased unions: %1%") % nrOpUpdateValuesCopied); + printMsg(v, format(" symbols in symbol table: %1%") % symbols.size()); + printMsg(v, format(" size of symbol table: %1%") % symbols.totalSize()); + printMsg(v, format(" number of thunks: %1%") % nrThunks); + printMsg(v, format(" number of thunks avoided: %1%") % nrAvoided); + printMsg(v, format(" number of attr lookups: %1%") % nrLookups); + printMsg(v, format(" number of primop calls: %1%") % nrPrimOpCalls); + printMsg(v, format(" number of function calls: %1%") % nrFunctionCalls); + + if (countCalls) { + v = lvlInfo; + + printMsg(v, format("calls to %1% primops:") % primOpCalls.size()); + typedef std::multimap<unsigned int, Symbol> PrimOpCalls_; + PrimOpCalls_ primOpCalls_; + foreach (PrimOpCalls::iterator, i, primOpCalls) + primOpCalls_.insert(std::pair<unsigned int, Symbol>(i->second, i->first)); + foreach_reverse (PrimOpCalls_::reverse_iterator, i, primOpCalls_) + printMsg(v, format("%1$10d %2%") % i->first % i->second); + + printMsg(v, format("calls to %1% functions:") % functionCalls.size()); + typedef std::multimap<unsigned int, ExprLambda *> FunctionCalls_; + FunctionCalls_ functionCalls_; + foreach (FunctionCalls::iterator, i, functionCalls) + functionCalls_.insert(std::pair<unsigned int, ExprLambda *>(i->second, i->first)); + foreach_reverse (FunctionCalls_::reverse_iterator, i, functionCalls_) + printMsg(v, format("%1$10d %2%") % i->first % i->second->showNamePos()); + + printMsg(v, format("evaluations of %1% attributes:") % attrSelects.size()); + typedef std::multimap<unsigned int, Pos> AttrSelects_; + AttrSelects_ attrSelects_; + foreach (AttrSelects::iterator, i, attrSelects) + attrSelects_.insert(std::pair<unsigned int, Pos>(i->second, i->first)); + foreach_reverse (AttrSelects_::reverse_iterator, i, attrSelects_) + printMsg(v, format("%1$10d %2%") % i->first % i->second); + + } +} + + +} |